LOUD Rattle in 4th gear at low RPM
2006, 6.0, 108k, only aftermarket is K&N Intake...
Truck drives fine but When I accelerate up to 40mph, then let off the gas to cruise around a corner (for example), then press the gas to accelerate there is a loud rattle (It sounds like a bunch of marbles being shook in a tin can). It sort of feels like a small lag while its making the noise. If I put the pedal to the floor, the engine does accelerate, but the noise grows louder until it downshifts to accelerate, then the noise is gone. This rattle happens EVERY time I am cruising at around 40mph then press the gas.
Any ideas on what this is and how to fix it would be awesome. Thanks guys!